An AEI zeolite is an artificially synthesized crystalline aluminosilicate and has been studied as a catalyst for olefin production and a catalyst for selective catalytic reduction (a so-called SCR catalyst) (Patent Document 1). The following methods are disclosed as methods for producing an AEI zeolite.
Patent Document 1 discloses a method for producing an AEI zeolite, the method including crystallizing a mixture containing sodium silicate and a Zeolite Y, and the AEI zeolite having a molar ratio of silica to alumina of greater than 10 (hereinafter, also referred to as “SiO2/Al2O3 ratio”). It is disclosed that the production method according to Patent Document 1 takes 5 to 7 days for the crystallization to obtain the AEI zeolite.
Non-Patent Document 1 discloses a method for producing an AEI zeolite, the method including crystallizing a mixture containing sodium silicate and a Zeolite Y. Non-Patent Document 1 discloses that no AEI zeolite is obtained in the case where a mixture having the molar ratio of SiO2/Al2O3 other than 30 is crystallized.
Non-Patent Document 2 discloses a method for producing an AEI zeolite, the method including crystallizing a mixture containing sodium silicate and a Zeolite Y. The SiO2/Al2O3 ratio of the AEI zeolite is 18.2 and 14.8. It is disclosed that the production method according to Non-Patent Document 2 takes 7 days for the crystallization to obtain the AEI zeolite.
Patent Document 2 discloses a method for producing an AEI zeolite, the method including crystallizing a mixture containing tetraethyl orthosilicate as a silica source, aluminum nitrate, and hydrofluoric acid, and the AEI zeolite having an SiO2/Al2O3 ratio of greater than 100. The SiO2/Al2O3 ratio of the AEI zeolite is 532 and 466.
Non-Patent Document 3 describes a method for producing an AEI zeolite, the method including crystallizing a raw material containing a Zeolite Y and a tetraethylphosphonium cation. It is disclosed that the production method according to Non-Patent Document 3 takes 1 day for the crystallization to obtain the AEI zeolite.
Non-Patent Document 4 discloses a method for producing SSZ-39, the method including crystallizing a raw material containing a colloidal silica, a Zeolite Y, and a 1,1,3,5-tetramethylpiperidinium cation. It is disclosed that the production method according to Non-Patent Document 4 takes 66 hours or longer for the crystallization to obtain the AEI zeolite.
Non-Patent Document 5 discloses a method for producing SSZ-39, the method including crystallizing a raw material containing a USY zeolite and a 1,1,3,5-tetramethylpiperidinium cation. It is disclosed that the production method according to Non-Patent Document 5 takes 7 days for the crystallization to obtain the AEI zeolite. Furthermore, Non-Patent Document 5 discloses a method for producing SSZ-39, the method including crystallizing a raw material containing a USY zeolite, a copper-polyamine complex, and a 1,1,3,5-tetramethylpiperidinium cation. The crystallization time is not described.